Chimney-top.



F. L. J. BOETTGHER.

OHIMNBY rgol. APPLICATION FILED FEB.5, 1910.

Patented'May 9, 1911.

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UNITED STATES PATENT OFFICE.

GHIMNEY-TOP.

Specification of Letters Patent.

Patented May 9, 1911.

Application filed February 5, 1910.` Serial No. 542,230.

To all whom t may concern:

Be it known that I, Flammen L. J. Bon'rr- CHER, a citizen of the UnitedStates, and a resident of /Vashington, in the District of Columbia, haveinvented certain new and useful Improvements in Chimney-Tops, of whichthe following is aspecification.

This invention is an improvement irfchimney tops having for an object toprovide simple means whereby to promote and facilitate the escape ofsmoke in all kinds of wind and weather, thus initiating and enhancingthe natural draft incident to the rise of heated air, also to providemeans for preventing the striking back of the smoke down the chimney;and the invention consists in certain novel constructions andcombinations of parts as will be hereinafter described and claimed:

In the drawing Figure 1 is a side view and Fig. 2 is a verticallongitudinal section of a chimney top embodying my invention and Fig. 3is a cross section on about the line 3-3 of Fig. 1 and Fig. L shows adifferent form of supporting device from that illustrated in Figs. 1 and2.

In the construction shown, the top comprises a body A, whose lower endis flared outwardly at A in trumpet like form and is adapted to fit atits lower outer edge against the wall of the chimney flue B, while theupper end of the body A flares outwardly in trumpet form at A2 and ispreferably formed with a greater' flare than the lower end of the bodyso that the said upper end A2 will be of greater diameter than the lowerend of the body, thus increasing the area of the exit end of the bodyand affording an outwardly flaring surface at A3 within the said trumpetlike end A2 of the body to render easier the arrangement of parts insuch manner as to prevent wind currents from blowing down the body Awhen the cover is applied, as shown in Figs. 1 and 2.

The cover C is supported by the straps D from the body A and I usuallyemploy three straps D and rivet them in the manufacture of the device tothe cover C and then rivet the straps at D to the body A after thelatter has been adjusted to the chimney top. In forming the cover C, itis usually rounded at the center and presents a concave form at it lowerend for impingement by the heated air and smoke as it rises from thebody A and the outer edges of the cover C tip downward and are in suchrelation to the upper end of the body A that lateral draft from anydirection outside the top and passing between the upper end of the bodyA and the edge C of the cover C will not blow down the body A but willstrike an outwardly flared surface at A3 within the trumpet like upperend of the body A and thus be directed upwardly and out of the top at apoint diametrically opposite the entrance of the currents as indicatedin Fig. 2 of the drawing so the wind will not at any time blow down thetop A of the chimney to produce a smoky chimney. In securing thisresult, the area of exit between the upper end of the body A and thecover should be no less than twice the interior area of the neck or bodyor more than three times the same, and the said space must therefore becomparatively narrow in order that the draft will not strike within thesurface A below the outwardly flared part thereof.

From the description before given, it will be noticed that the body A iscomparatively contracted at its middle portion and flares outwardlytoward its lower end to freely receive the smoke and flares outwardly inthe trumpet like expansion at its upper end to facilitate the dischargeof the smoke and to secure the outward discharge of any wind currentsthat may enter between the top and the cover. The contraction at themiddle portion of the body condenses the smoke at such point anddelivers it to the upper trumpet like portion whence it may bedischarged below the cover as will be understood from the foregoingdescription.

The body A is provided above its lower trumpet like portion with alateral annular' flange E which rests upon the chimney B and forms belowit and between the said 'flange and the lower end of the body A a recesswithin the flue B and receiving cement F by which the top may besecurely held in position.

In placing the top A upon a chimney, some of the top layer of bricks B2may be omitted, enough being left to support the Harige E and then afterthe cement F has been supplied to the recess surrounding the lower endof the body within the flue B the bricks may be supplied below theflange E to form the top course of the chimney and properly secured inplace by mortar, cement or otherwise, as desired. The connection of thebody with the chimney is thus facilitated by the trumpet like form atthe lower end of the body in connection with means shown as the flange Efor resting upon the chimney and holding the top from downwarddisplacement.

The invention is simple, easily constructed and applied to a chimney andefficiently serves the purpose for which it is designed.

Instead of the flange E, three angle irons such as shown in F ig. 4: maybe employed such outer edge of the cover is in the direc-V tion of thefilare of the upper portion of the body in such manner as to incre-asethe suc tion-like effect resulting from the special relation of thecover and the fiared edge of the body. It will further be noticed thatthe cover has a; rounded crown portion and an edge or rim portion whichis formed flat or on a straight line in cross section. This results indecreasing the resistance to the air striking laterally from any side,as well as decreasing the tendency of the air to rise from the upperside of the cover at the center thereof, and permits the air to passover the crown of the cover and down the opposite sloping side. At thesame time the under side of the cover with the rounded central portionand the straight edge portion aids in preventing the air currents frombeing deflected downwardly into the body of the chimney.

vrlhe cover being substantially above the body portion, occupies such arelation to the outwardly flaring edge of the body as to permit thepassage of air transversely below the cover and over the body and ifsuch air should be directed downwardly into the body it will not strikebelow the outwardly flaring body portion but will be directed upwardlythereby.

The physical laws involved in the operation of the device are that acurrent obstructed will take the course of the least resistance and thatthe angle of reflection is equal. to the angle of incidence.

' I claim:

A chimney top comprising a body portion having its upper end flaredoutwardly in trumpet-like form and having on its inner side an outwardlyfiared surface and a cover secured upon thc body and having a rounded orcurved central portion, and an edge or rim portion which is fo-rmed flator on a straight line in cross section, the said cover being securedupon the body and practically above the said body with the outer edge ofthe cover inv close proximity to the outer edge of the outwardly flaredportion of the body and in the direction of the flare of suc-h edge ofthe body with the outer edge of the cover disposed in such relation to.the upper outer edge of the body portion that draft entering betweensaid edges cannot strike the inner flared surface of the lbody at apoint below that at which the outward flare of the body begins and thecover being practically above the body portion whereby to permit thepassage of air transversely below the cover and over the body, allsubstantially as and for the purposes set forth.

FREDRICK L. J. BOETTCHER.

Vitnesses:

SoLoN C. KEMON, PERRY B. TURPIN.

Copies of this patent may be obtained for ve cents each, by addressingthe Commissioner of Patents. Washington, D. C.

